<!DOCTYPE html>
<html>

<head>
  <title></title>
  <script type="text/javascript">
  // 基本用法
  let a = 10;
  console.log(a++);

  for (let i = 0; i < 10; i++) {
    console.log(i); // 0,1,2,3,4,5,6,7,8,9
  }

  var b = [];
  for (let i = 0; i < 10; i++) {
    b[i] = function() {
      console.log(i);
    };
  }
  b[6](); // 6
  </script>
</head>

<body>
</body>

</html>